Angiogenin is a 14 kDa non-glycosylated polypeptide which is produced by several growing cell types including vascular endothelial cells, aortic smooth muscle cells, fibroblasts, and some tumours such as colon carcinomas, ovarian carcinomas, and breast cancers. Angiogenin has been isolated from a number of sources including normal human plasma, bovine plasma, bovine milk, and mouse, rabbit and pig sera. In each of these sources angiogenin is present at low levels (less than 12 mg/L in bovine milk and less than 150 μL/L in human plasma).
As well as a potent stimulator of angiogenesis, angiogenin has been shown to possess a number of other activities. These include the ability to remove skin defects such as pigmented spots, modulation of immune responses, protection of polymorphonuclear leukocytes from spontaneous degradation, and microbicidal activity against systemic bacterial and fungal pathogens. Based on the known physiological functions of the protein, various angiogenin applications in medicine, dietary foodstuff supplements and cosmetics can be predicted.
The use of angiogenin in such applications requires an efficient method for the preparation of the protein on a commercial scale from an appropriate source. It is an aim of a preferred embodiment of the present invention to provide such a method.